Co-catalytic effect of Al-Cr pillared montmorillonite as a new SCR catalytic support

BACKGROUND It is of great interest to use pillared clay (PILC) as a cheap support for a selective catalytic reduction (SCR) catalyst. Al‐Cr pillared clay (AlCr‐PILC) has high thermal stability due to the introduction of polycations of Al. As a support, AlCr‐PILC may show a co‐catalytic effect in SCR processes because chromium oxide itself is an active SCR catalyst. The aim of this work is to investigate the potential of AlCr‐PILC as a new low temperature SCR catalyst support. RESULTS A series of AlCr‐PILC with Al:Cr molar ratio varying from 0:4 to 4:0 were successfully synthesized to support manganese and cerium active phase. MnCe/AlCr(2:2)‐PILC exhibited the highest NOx conversion close to 100% at 200–300 °C, and more than 90% N2 selectively over a wide temperature window of 140–300 °C. The catalytic activity of MnCe/AlCr‐PILC in terms of both NOx conversion and N2 selectivity is much higher than those of MnCe/Al‐PILC, MnCe/Cr‐PILC, AlCr‐PILC, and the simple mixed MnCeAlCr, indicating the co‐catalytic effect of AlCr‐PILC support. CONCLUSION AlCr‐PILC is a very promising low‐temperature SCR catalyst support. The XRD, XPS, and H2‐TPR measurements prove that the co‐catalytic effect of AlCr‐PILC occurred via the strong interaction between MnCe and the AlCr‐PILC support. © 2016 Society of Chemical Industry